多成分系無アルカリガラスの表面結晶化に及ぼす外部添加剤の役割

抄録

The crystallization behavior of a glass in the SiO₂-Al₂O₃-CaO-ZnO-TiO₂-B₂O₃ system with additives was investigated by means of DTA, XRD and SEM observation. The additives were wollastonite, silica, lime, Fe₂O₃, alumina, zirconia, zircon, 36.6CaO⋅63.4SiO₂ glass, titania, montmorillonite, kaolin, talc, zeolite. The main results are as follows. (1) The most effective additives that reduced the double peaks of DTA curve into a single one were wollastonite, TiO₂ and 36.6CaO⋅63.4SiO₂ glass. Among them, only external addition of wollastonite shifted the peak temperature downward. (2) Crystal precipitation was enhanced on the wollastonite contacted glass surface. (3) The precipitated crystalline phase was speculated to consist of tiny particles of anorthite, gehlenite, willemite and titanite crystals.